Mustard Dip for Pretzels

1/4 cup mayonnaise
1/4 cup prepared yellow or Dijon mustard
2 tablespoons finely chopped onion
1 tablespoon ranch salad dressing mix
2-1/4 teaspoons prepared horseradish

In a large bowl, combine the mayonnaise, mustard, onion, salad dressing mix and horseradish. Cover and refrigerate for at least 30 minutes. Serve with pretzels. 

Yield: about 1/2 cup.